Yi-Chu Liao1, Yung-Song Wang2, Yuh-Cherng Guo3, Wen-Lien Lin2, Ming-Hung Chang1, Suh-Hang Hank Juo4. 1. Section of Neurology, Taichung Veterans General Hospital, Taichung, Taiwan; Department of Neurology, National Yang-Ming University School of Medicine, Taipei, Taiwan. 2. Department of Genome Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. 3. Neuroscience Laboratory, Department of Neurology, China Medical University Hospital, Taichung, Taiwan; School of Medicine, Medical College, China Medical University, Taichung, Taiwan. 4. Department of Genome Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Medical Research and Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. Electronic address: hjuo@kmu.edu.tw.
Abstract
OBJECTIVES: The present study aimed to explore the role of microribonucleic acid (miRNA) Let-7g in regulating endothelial functions. BACKGROUND: Derangement of miRNAs is implicated in the pathogenesis of cardiovascular diseases. Because the transforming growth factor (TGF)-β pathway plays a regulatory role in endothelial functions, miRNAs targeted at TGF-β signal cascade might affect vascular health. METHODS: Bioinformatics software predicted that Let-7g can influence the TGF-β pathway by targeting 3 genes. The Let-7g's effects on multiple endothelial functions were first tested in endothelial cells (ECs) and then in apolipoprotein E knockout mice. Blood samples from lacunar stroke patients were also examined to further support Let-7g's effects on human subjects. RESULTS: Let-7g was experimentally confirmed to knock down the THBS1, TGFBR1, and SMAD2 genes in the TGF-β pathway. PAI-I, one of the downstream effectors of the TGF-β pathway, was also down-regulated by Let-7g. Let-7g decreased EC inflammation and monocyte adhesion and increased angiogenesis via the TGF-β pathway. Furthermore, Let-7g reduced EC senescence through increasing SIRT-1 protein. Venous injection of Let-7g inhibitor into apolipoprotein E knockout mice caused overgrowth of vascular intima-media, overexpression of PAI-1, increased macrophage infiltration, and up-regulation of TGF-β downstream genes in the carotid arteries. Let-7g's beneficial effects on EC were reduced, whereas the TGF-β pathway was suppressed by ribonucleic acid interference. Restoration of the TGF-β pathway also attenuated the effects of Let-7g overexpression. Low serum levels of Let-7g were associated with increased circulating PAI-1 levels. CONCLUSIONS: Decreased Let-7g levels impair endothelial function and increase the risks of cardiovascular diseases through targeting TGF-β and SIRT-1 signaling.
OBJECTIVES: The present study aimed to explore the role of microribonucleic acid (miRNA) Let-7g in regulating endothelial functions. BACKGROUND: Derangement of miRNAs is implicated in the pathogenesis of cardiovascular diseases. Because the transforming growth factor (TGF)-β pathway plays a regulatory role in endothelial functions, miRNAs targeted at TGF-β signal cascade might affect vascular health. METHODS: Bioinformatics software predicted that Let-7g can influence the TGF-β pathway by targeting 3 genes. The Let-7g's effects on multiple endothelial functions were first tested in endothelial cells (ECs) and then in apolipoprotein E knockout mice. Blood samples from lacunar strokepatients were also examined to further support Let-7g's effects on human subjects. RESULTS:Let-7g was experimentally confirmed to knock down the THBS1, TGFBR1, and SMAD2 genes in the TGF-β pathway. PAI-I, one of the downstream effectors of the TGF-β pathway, was also down-regulated by Let-7g. Let-7gdecreased EC inflammation and monocyte adhesion and increased angiogenesis via the TGF-β pathway. Furthermore, Let-7g reduced EC senescence through increasing SIRT-1 protein. Venous injection of Let-7g inhibitor into apolipoprotein E knockout mice caused overgrowth of vascular intima-media, overexpression of PAI-1, increased macrophage infiltration, and up-regulation of TGF-β downstream genes in the carotid arteries. Let-7g's beneficial effects on EC were reduced, whereas the TGF-β pathway was suppressed by ribonucleic acid interference. Restoration of the TGF-β pathway also attenuated the effects of Let-7g overexpression. Low serum levels of Let-7g were associated with increased circulating PAI-1 levels. CONCLUSIONS: Decreased Let-7g levels impair endothelial function and increase the risks of cardiovascular diseases through targeting TGF-β and SIRT-1 signaling.
Authors: J L Marques-Rocha; M Garcia-Lacarte; M Samblas; J Bressan; J A Martínez; F I Milagro Journal: J Physiol Biochem Date: 2018-05-22 Impact factor: 4.158